Surface and center indicator



J. A. NELL.

SURFACE AND CENTER lNDiCATOR,

APPLICATION-FILED Mula-1919.

1,380,580, I Patented June 7, w21.

nur stares' TENT N JAMES A.: NELL, or NEW BRITAIN, CONNECTICUT.

SURFACE AND CENTER INDICATOR.

assenso.

Specification of Letters Patent.

Patented aan@ a', ieai.

Application filed March 25, 1919. "Serial No. 284,925.

tion, such as will enable others skilled in.

f the art to which it appertains to make and use the same.y v n rlhis invention' relates to improvements in surface and center indicators, one object of the invention being to provide an efficient instrument for ascertaining the variations of a given plane, arc or center of mechanical and structural objects, and to combine the feature of a surface and center indicator in compact and useful form.

A. further object is to provide simple and eflicient means for securing the instrument to suitable tool posts or other fixtures to enable the operator to readily adjust the instrument with the dial in position for easy observation.

With these and other objects in view the invention consists in certain novel features of construction and combinations of parts as hereinafter set forth and pointed out in the claims. n i

In the accompanying drawings; Figure 1 is a. view in elevation of an instrument embodying my invention; Fig. 2 is a view in section on the line 2 2 of Fig. 5; Fig. 3 isa view in section on the line 3 3 of Fig. 5; Fig. 1 is a view in section on the line 1 4 of Fig. 5; Fig. 5 is a sectional view on the line 5 5 of Fig. 1; Fig. 6 is a plan view of the lower casing member; Fig. 7 4is a view in section on the line 7 7 of Fig. 6; and Figs. 8, 9, 10, 11 and 12 are` detail views.

1, 2 represent upper and lower frame cas--l ing members respectively, which are superimposed one upon `the other and formed with openings of irregular shape to accomy v one end to a pin 29 on said pinion, the other modate the mechanism of the instrument. The respective frame members 1, 2 are made with mating grooved arms asrindicated at 3 to form a rod-bearing as hereinafter explained and with spaced arms or fingers 4-4 between which a contact element is movable and by which said element is protected.

A plate 5 having a configuration corresponding with that of the irregular opening in the `lower frame plate 2 enters said irregular opening and a similarly-shaped platek 61s located in the irregularly-shaped opening of the upper frame plate 1, the

irregularly-shaped plates 5 and 6 being so disposed relatively to each other as to leave space between them forthe accommodation of parts of the mechanism mounted on the lower plate'5. A. dia-l plate 7 is located over thejupper plates 1 and 6, and a frame S spaces a transparent disk 9 and a top plate 10 from the dial plate 7 said top plate having an opening 11 through which the dial plate and a pointer which coperates therewith can be seen.` A base plate 12 is provided for the instrument, and fastening devices such as indicated 'at 13 serve to secure the several parts of the casing or framework in assembled position.

A. lever 1/1y (which constitutes a contact member.) is pivotally mounted on a pintle k15 on the plate 5 and the forwardly proliecting armfof this lever is made with a head 16 .having three Contact portions a, 50.

The member or portion 17 of the lever,

which extends rearwardly of the pivotal mounting 15, is disposed between the plates 5 6 and is provided at lits rear end with a hook-shapedv arm 18, the portion 17 of said lever being also provided, intermediate of its ends, with a V-shaped tooth 19 and a V-notch 20.

A lever 21 is lmounted on a pintle 22 on the plate 5 and at one side of its pivotal mounting, said lever is provided with a tooth 23 in position to bey engaged by the free end of the arm 18 of the lever member 17. lAt the free end ofthe long arm of the lever 21, a toothed segment or rack 24E is provided and meshes with a pinion 25. A pintle 26 is provided on the plate 5 for the accommodation of the hub of the pinion 25 and to said hub, a pointer 27 is attached and adapted to coperate with the scale on the dial plate 7. A spring 28 (Fig. 2) encircles the hub of the pinion 25 and is attached at indicated at 34-35. rlhe bar 33 is provided with a rod 36 which is slidingly mounted in the bearing formed by the grooves in the arms 3 of the framework and to the free end of this rod, a knob 37 is secured. The longitudinal movement of the bar 33 and its rod 36 is limited by a pin 38 Which passes transversely through a groove 39 in said rod as shown in Fig. 3. rllhe bar 33 is made at one end with an enlargement 40 having a V-notch 41 in Which one pointed end of a rod 42 has a bearing, the -other pointed end of said rod having a bearing in a V-notch 43 near the free end of the arm 44 of the bell-crank lever 31. T he arm 45 of the bellcranlr lever is provided near its free end with a lf-notch 46 into Which one pointed end of a rod 47 has a bearing, the other pointed end of this rod having a bearing in the V-notch 20 of the lever member 17. The rods 42 and 47 are notched Where they pass each other as at 43 (Figs. 9 and 10) to avoid conflict with each other and the bar 33 is notched as at 4.9-50 for the accommodation of the rod 47 and the arm 44 of the bellcrank lever.

Stop pins d may be employed for limiting the movements of the pivoted parts of the instrument.

A shank 51 is secured to the base plate 12 of the instrument and provided with a ballhead 52 and to effect a universal coupling between this headed shank and a rod 53 to be secured to a tool post or other part of a machine, the coupling devices noiv to be described will be found eilicient. A plate 54 having a socket near one end to receive the ball head 52 and a socket near its other end te receive a ball-head 55 on the rod 53, is provided and the ball heads are retained in said sockets by a plate 5G. A screv;7 57 passes freely through a hole in the plate 54 and is threaded through the plate 56, Whereby the balleheads 52 and 55 may be clamped between said plates. Guide pins 58 are secured to the plate 54 and pass freely through holes in the plate 56. By means of these coupling devices, the instrument may be adjustably connected With a machine and read ily manipulated when in use.

The operation of the instrument is as follows After attaching` the instrument through the coupling devices, to a suitable support, such for example, as the tool post of a lathe, shaper or other machine, one of the contact portions a, `7), o or 37 will be brought in contact with the surface to be tested. 1f the portion of the contact head 16 be used, the lever 14 will be moved in the direction of c, and the portion 17 of said lever Will move in the reverse direction, thus causing the lever 21 to be turned on its pivotal support and impart motion to the gear 25 in clock- Wise direction and causing movement of the pointer 27 relatively to the scale. When the pressure of the lever 14 against the Work is Withdrawn, the spring 23 will return the pointer and the parts which actuate it, to normal positions. Should the contact portions c of the head 16 be used in testing a surface, the lever 14 Will be moved in the opposite direction and the tooth 19 on the portion 17 of said lever Will cause the lever 21 to be moved and movement to be imparted to the pointer in the same direction as previously described. Y

To ascertain the accuracy of the center of a piece held in a chuck 0r on a face plate of a machine, the point t of the Contact head 16 Will be inserted into the center mark; then pressure will be applied to move the lever in either direction ZJ or c until the pointer registers Zero on the scale and then revolve the piece and the eccentricity of the center mark Will vibrate the lever 14 and the pointer will be moved accordingly.

rEhe pointed contact head is admirably adapted for use in entering small holes, lcenters or narrow spaces, but Where space is less limited, the knob or contact head 37 may be employed, and in such case, the instrument would be operated as follows: .Pressure applied at 37 will cause longitudinal movement of the bar 33, and this movement will be transmitted by the rod 42 to the bell-crank lever 31, and movement of the latter will be transmitted by the rod 47 to the portion 17 of the lever 14. Such movement of the lever 14-17 will be transmitted by the tooth 19 to the lever 21 and movement of the latter will cause movement of the pointer through the medium of the rack-and-pinion gearing.

Various slight changes might be made in the details of construction of my invention Without departing from the spirit thereof or limiting its scope and hence 1 do not Wish to restrict myself t0 the precise details herein set forth.

Having fully described my invention What l claim as new and desire to secure by Letters-Patent, is

1. In a device of the character described, the combination with a frame, a pointer, a spring for retaining said pointer in and returning it to normal position, a pivoted lever,

and means between said pivoted lever and pointer for transmitting movement to the latter, of a second lever cooperating With said first-mentioned lever, a sliding bar, a contact head connected With said bar, a bellcrank lever, a rod having pivotal connection with said bar and With onel arm of the bell- I pointer for transmitting movement to the latter, of a second lever coperating with said first-mentioned lever at respective sides of the fnlcrnm of the latter and provided with a contact portion, a sliding bar7 a bell-crank lever, a rod between said sliding bar and one arm of the bell-crank lever, and a rod between the other arm of said bell-cranl-lever and said second lever.

3. In a device of the character described, the combination of a frame comprising plates having openings therein, other plates mounted in said openings, a dial plate on said frame and a top plate over the dial plate and having an opening through which the dial plate may be viewed, of a lever pivoted between said other plates and provided with a Contact head, a pointer coperable with the dial of said dial plate, a spring for retaining said pointer in and returning it to anormal position, and mechanism between said other plates for transmitting movenient of said lever and its contact head to said pointer. y

In testimony whereof, I have signed this specification in the presence of two subscrib ing witnesses.

JAMES A. NELL.y 

